The air guide device of the general type in question is known from, for example, DE 10 2006 014 260 A1. The known air guide device comprises an air guide body arranged essentially in the center, on which two lateral air guide body sections are arranged, which can be moved in the transverse direction of the vehicle. The air guide device can be adjusted between a retracted, nonoperating position and an extended, operating position, where the two lateral air guide body sections are extended when the air guide device is in the operating position and thus increase the air guide surface available for generating downforce.
An air guide device for a motor vehicle which comprises a spoiler is also known from DE 10 2004 030 571 B4. An adjusting device is able to move the spoiler between a nonoperating position, in which it lies essentially within the contour of the vehicle, and an operating position, in which it projects above the contour of the vehicle. The spoiler surface of the spoiler can be increased by spoiler sections which can be extended laterally.
Finally, an air guide device for a vehicle is known from DE 10 2005 030 203 A1, which, to improve the downforce, comprises spoiler blade sections on a rear axle, these blade sections being extendable in the transverse direction of the vehicle. In its operating position, the spoiler blade extends out from both sides of the central part of the body in the area of the side parts or fenders of the vehicle.